1. Field of the Invention
The present invention relates to a manufacturing method and a manufacturing apparatus of a device, which are used for precisely forming a microscopic wiring structure.
2. Description of Related Art
In the related art, aluminum or an aluminum alloy was used as a microscopic wiring material for a semiconductor device and the like formed on a substrate. However, since aluminum has a low melting point and poor migration resistance, it was difficult to meet high integration and increase in a speed required for a semiconductor device.
For this reason, copper has been used as a wiring material in recent years. Although copper is excellent as an LSI wiring material since copper has a higher melting point as compared with aluminum and has low electrical resistivity, it is known that copper is a material on which it is difficult to perform microfabrication. A method for performing microfabrication on a wiring (copper wiring) configured by copper is disclosed in Japanese Unexamined Patent Application, First Publication No. 2011-086825. According to Japanese Unexamined Patent Application, First Publication No. 2011-086825, it is possible to form a copper wiring inside a microscopic groove by forming the groove in an insulating later, embedding copper inside the groove by using a sputtering method, and then removing excess copper protruding out of the groove.
However, the invention disclosed in Japanese Unexamined Patent Application, First Publication No. 2011-086825 has a problem in that it is difficult to embed copper inside the microscopic groove without any gaps. That is, when copper deposited using the sputtering method is embedded inside the groove, an amount of copper deposited on the deepest side inside the groove tends to be smaller than an amount of copper deposited on the side of an opening end. As a result, a cavity may be generated on the deepest side inside the groove.
In addition, when copper melted by using a reflow method is embedded inside the groove, there is a problem in that wettability of melted copper with respect to a barrier metal layer formed in advance on an inner wall surface of the groove is poor and copper is solidified in a state in which a cavity is generated inside the groove.
In any case, a resistance value of the copper wiring rises if a cavity is generated in the copper wiring formed inside the groove, and there is also a possibility of disconnection.